Chemical Hydrogen Storage using Ultra-High Surface Area Main

Group Elements (part of the DOE Chemical Hydrogen Storage

Center of Excellence)

Philip P. Power (pppower@ucdavis.edu) and Susan M. Kauzlarich (smkauzlarich@ucdavis.edu)

University of CaliforniaMay 16, 2006

Project ID #STP 26This presentation does not contain any proprietary or confidential information

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Overview--Innovation Beyond Boron

• Cost• Weight and volume• Hydrogen capacity

• Total project funding– DOE share– Contractor share $0.5 M

• Funding for FY05$100K (DOE) $ $20K (cost share)

• Funding for FY06– $193K (DOE) $40K (cost share)

Timeline

Budget

Barriers

• Participant in the DOE Chemical Hydrogen StorageCenter of Excellence

• LANL, PNNL, Penn, Alabama

Direct Collaborators

Targets• Gravimetric capacity: >8%

Project Start Date: FY05Project End Date: FY0920 % complete

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• To identify hydrogen storage material enabling DOE targets and increase the understanding of synthetic approaches and physical properties of main group element clusters, such as Si, B, Al, and alloys thereof, BP and BN compounds.

• To design simple routes to such compounds using mild conditions to provide commercially viable materials.

• To investigate the viability of the synthesized materials for commercial application by studying weight and volume as well as the reversibility of hydrogen uptake.

• To analyze measurements to identify compounds that offer relatively lightweight, easily handled solid materials capable of hydrogen storage that are synthesized, activated and regenerated in a simple manner.

Overall

2005-2006

2007-2009

Objectives – Innovation Beyond Boron

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Approach

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1) Room temperature synthesis of amide-capped silicon nanoparticles (Task 1)

2) Solution and solid-state synthesis of nanocrystalline silicon with hydrogen (Task 1)

3) First synthesis of organo-capped boron nanoparticles (Task 1)

4) Synthesis of molecular compounds by addition of hydrogen across a multiply-bonded system (Task 2)

Results

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Six(NH2)n --> SixNn + nH2

SiCl4 + Na.naphthalenide (Cl)nglyme

+ NaCl

(Cl)nNH3 (g)

(NH2)n + NH4Cl

20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

Inte

nsity

(a.u

.)

2θ

Si Standard Si-NH

2 nanoparticles

29Si NMR

EDX

Results-1

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Results - 2Solution Route Solid State Route

3500 3000 2500 2000 1500 10000.0

0.1

0.2

0.3

0.4

0.5

0.6

Tran

smita

nce

Wavenumbers (cm-1)

Si-DME

Si-H

SiHn --> Si + n/2 H2

CP 29Si NMR

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Boron Nanoparticles

11B NMRA.L. Pickering, C. Mitterbauer, N.D. Browning, S.M. Kauzlarich, P.P. Power, Nature Materials, submitted

Results - 3

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Facile Activation of Dihydrogen by an Unsaturated Heavier Main Group Compound G.H. Spikes, J.C. Fettinger, P.P. Power JACS, 2005

Crystal structure determined

Molecular Compounds Results - 4

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Future Work• FY05-06

– Prepare hydrogen and amine terminated Si nanoparticlesand characterize. Investigate alloy nanoparticle synthesis and characterize.

– Prepare main group compounds and characterize.• FY07

– Determine the most promising composition with highest hydrogen gravimetric amount. Explore reaction mechanism and prepare materials in high yield.

• FY08– Provide materials to partners for testing.

• FY09– Optimize synthesis for further testing.

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TimelineTask Year

1Year 2

Year 3

Year 4

Year 5

Task 1: Nanoparticle SynthesisSynthesis of SiH and Si(NH2)Characterization of SiH and Si(NH2)Synthesis of Si1-xMxH and Si1-xMNH2

Characterization of Si1-xMxH and Si1-xMNH2 composition and reactivityOptimization of reaction to provide material to partners

Task 2: Main group Compound SynthesisSynthesis of (H2BXH2)nCharacterization of composition and reactivityexplore main group analogs

Task 3: Characterization and TestingTest reactivity and thermolysis of various alloys and main group compounds

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Summary• Amide capped and hydrogen capped Si nanoparticles

have been synthesized by two different low temperature routes.

• These nanoparticles have been shown to evolve substantial amounts of gas when heated.

• Boron nanoparticles capped with -OR groups have been synthesized by a low temperature route.

• H2 has been shown to react with a “digermyne”,RGeGeR at room temperature and pressure.

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Publication List

1. Facile Activation of Dihydrogen by an Unsaturated Heavier Main Group Compound G. H. Spikes, J. C. Fettinger, P. P. Power, JACS 2005, 127, 12232.

2. Nanocrystalline Silicon for Hydrogen StorageD. Neiner, C. N. Chervin, H. W. Chiu, M. J. Blessent, S. M. Kauzlarich, 2006 MRS Spring Meeting, San Francisco, CA, April 17 - 21, 2006, EE3.19.

2. Room Temperature Synthesis of Surface-Fuctionalised Boron NanoparticlesA. L. Pickering, C. J. Mitterbauer, N. D. Browning, S. M. Kauzlarich, P. P. Power, Nature Materials 2006, submitted.